[PATCH 08/10] dma: imx-sdma: extract common sdma prep code

From: Joshua Clayton
Date: Mon Jun 15 2015 - 12:20:00 EST


Extract the code that is equivalent between
the slave and cyclic sdma functions.
Add some better errors for failure conditions.

Signed-off-by: Joshua Clayton <stillcompiling@xxxxxxxxx>
---
drivers/dma/imx-sdma.c | 76 +++++++++++++++++++++-----------------------------
1 file changed, 32 insertions(+), 44 deletions(-)

diff --git a/drivers/dma/imx-sdma.c b/drivers/dma/imx-sdma.c
index c9badd4..4d447be 100644
--- a/drivers/dma/imx-sdma.c
+++ b/drivers/dma/imx-sdma.c
@@ -1018,6 +1018,34 @@ static int sdma_alloc_chan_resources(struct dma_chan *chan)
return 0;
}

+int sdma_prep_common(struct sdma_channel *sdmac, int buf_count,
+ enum dma_transfer_direction direction)
+{
+ struct sdma_engine *sdma = to_sdma_engine(sdmac);
+
+ if (sdmac->status == DMA_IN_PROGRESS) {
+ dev_err(sdma->dev, "SDMA channel %d: dma already in progress\n",
+ sdmac->channel);
+ return -EBUSY;
+ }
+
+ sdmac->status = DMA_IN_PROGRESS;
+ sdmac->buf_tail = 0;
+ sdmac->direction = direction;
+
+ dev_dbg(sdma->dev, "setting up %d entries for channel %d.\n",
+ buf_count, sdmac->channel);
+
+ if (buf_count > NUM_BD) {
+ dev_err(sdma->dev, "SDMA channel %d: maximum number of buffers exceeded: %d > %d\n",
+ sdmac->channel, buf_count, NUM_BD);
+ return -EINVAL;
+ }
+ sdmac->num_bd = buf_count;
+
+ return sdma_load_context(sdmac);
+}
+
static void sdma_free_chan_resources(struct dma_chan *chan)
{
struct sdma_channel *sdmac = to_sdma_chan(chan);
@@ -1053,28 +1081,12 @@ static struct dma_async_tx_descriptor *sdma_prep_slave_sg(
int channel = sdmac->channel;
struct scatterlist *sg;

- if (sdmac->status == DMA_IN_PROGRESS)
- return NULL;
- sdmac->status = DMA_IN_PROGRESS;
-
- sdmac->flags = 0;
-
- sdmac->buf_tail = 0;
-
- dev_dbg(sdma->dev, "setting up %d entries for channel %d.\n",
- sg_len, channel);
-
- sdmac->direction = direction;
- ret = sdma_load_context(sdmac);
+ ret = sdma_prep_common(sdmac, sg_len, direction);
if (ret)
goto err_out;

- if (sg_len > NUM_BD) {
- dev_err(sdma->dev, "SDMA channel %d: maximum number of sg exceeded: %d > %d\n",
- channel, sg_len, NUM_BD);
- ret = -EINVAL;
- goto err_out;
- }
+ sdmac->flags = 0;
+

sdmac->chn_count = 0;
for_each_sg(sgl, sg, sg_len, i) {
@@ -1129,7 +1141,6 @@ static struct dma_async_tx_descriptor *sdma_prep_slave_sg(
bd->mode.status = param;
}

- sdmac->num_bd = sg_len;
sdma->channel_control[channel].current_bd_ptr = sdmac->bd_phys;

return &sdmac->desc;
@@ -1149,33 +1160,11 @@ static struct dma_async_tx_descriptor *sdma_prep_dma_cyclic(
int channel = sdmac->channel;
int ret, i = 0, buf = 0;

- dev_dbg(sdma->dev, "%s channel: %d\n", __func__, channel);
-
- if (sdmac->status == DMA_IN_PROGRESS)
- return NULL;
-
- sdmac->status = DMA_IN_PROGRESS;
+ sdma_prep_common(sdmac, buf_len / period_len, direction);

- sdmac->buf_tail = 0;
sdmac->period_len = period_len;

sdmac->flags |= IMX_DMA_SG_LOOP;
- sdmac->direction = direction;
- ret = sdma_load_context(sdmac);
- if (ret)
- goto err_out;
-
- if (num_periods > NUM_BD) {
- dev_err(sdma->dev, "SDMA channel %d: maximum number of sg exceeded: %d > %d\n",
- channel, num_periods, NUM_BD);
- goto err_out;
- }
-
- if (period_len > 0xffff) {
- dev_err(sdma->dev, "SDMA channel %d: maximum period size exceeded: %d > %d\n",
- channel, period_len, 0xffff);
- goto err_out;
- }

while (buf < buf_len) {
struct sdma_buffer_descriptor *bd = &sdmac->bd[i];
@@ -1207,7 +1196,6 @@ static struct dma_async_tx_descriptor *sdma_prep_dma_cyclic(
i++;
}

- sdmac->num_bd = num_periods;
sdma->channel_control[channel].current_bd_ptr = sdmac->bd_phys;

return &sdmac->desc;
--
2.1.4

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/